ISSN 1875-3728, Geography and Natural Resources, 2012, Vol. 33, No. 4, pp. 298-303. © Pleiades Publishing, Ltd., 2012.
Original Russian Text © V.V. Khakhinov, B.B. Namsaraev, G.S-S. Dorzhieva, S.P. Buryukhaev, 2012, published in Geography and Natural Resources, 2012, Vol. 33, No. 4, pp. 65-71.
RESEARCH IN THE BAIKAL WATERSHED
Hydrochemical and Microbiological Characteristics
of Bog Ecosystems on the Isthmus of Svyatoi Nos Peninsula
(Lake Baikal)
b
V. V. Khakhinova, B. B. Namsaraevb, G. S-S. Dorzhievac, and S. P. Buryukhaevb
Baikal Institute of Nature Management, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
Institute of General and Experimental Biology, Siberian Branch, Russian Academy of Sciences, Ulan-Ude, Russia
c
Buryat State University, Ulan-Ude, Russia
e-mail: [email protected]
a
Received February 22, 2012
Abstract—Presented are the results from hydrochemical and microbiological investigations into Arangatui
bog ecosystems on the isthmus of Svyatoi Nos Peninsula on the shores of Lake Baikal. The formation features
of bog waters as a result of a rise in the lake’s water level.
DOI: 10.1134/S1875372812040075
Keywords: bog ecosystems, hydrochemical and microbiological investigations.
INTRODUCTION
Bogs with an accumulative character of exchange of
matter and energy possess one of the main carbon pools
of biosphere. The role played by bogs in the formation of
the atmospheric gas composition is commonly known:
the vegetation cover of the bog ecosystems across the
globe releases into the atmosphere up to 1.6*108 t of
oxygen per year; furthermore, the process involves
the formation of greenhouse gases, such as СО2 and
СН4. The source for gases is provided by biological
destruction of organic matter [1–3].
The evolution of most bogs is a relatively long
natural process which is an important constituent of
the functioning of a unified natural ecosystem. On the
other hand, water-logged areas are of rather widespread
occurrence, which have resulted from human economic
activity. The contemporary natural-anthropogenic bog
systems are in isolation; their existence is, on the one
hand, a naturally occurring process and, on the other,
they are evolving as a result of a direct or indirect
anthropogenic impact [1, 4–6]. Such formations are
exemplified by the ecosystems along the eastern shores
of Lake Baikal. Here, with a rise in the lake’s overall
water table caused by the hydraulic constructions on
the Angara river, the bog formation processes have
intensified [7, 8]. The implications of such processes
involve the formation of bog waters of a special kind.
Bog complexes are of intrinsic scientific
interest as a study area for investigating the naturalanthropogenic processes in the interactive mode where
the anthropogenic component is regarded as natural
conditions for the functioning of the overall ecosystem.
As an example we refer to the extensive areas of the
Arangatuiskii bog massif on the isthmus of Svyatoi
298
Nos Peninsula where a rise in Lake Baikal’s water table
caused changes in the development of the ecosystem as
a whole.
The present ecological status of biotopes in
conditions of a phreatic rise is due primarily to changes
in hydrological, hydrochemical, microbiological,
biological and other characteristics, and the objective
of this paper is to investigate these characteristics.
OBJECT AND METHODS
For the territory of the Arangatuiskii bog massif we
compiled the landscape-typological map identifying
the biogeocenoses with sampling sites (Fig. 1). Water
samples for analysis were collected from wells of each
bog phytocenosis. Point 1 – littoral portion of Lake
Mal. Arangatui, with the bottom covered by a layer
of decayed plant remains. Point 2 – bog biotope with
sedge/horse-tail vegetation; the bottom sediments are
comprised of weakly decomposed peat. Gases are
liberated at these two points. Point 3 – sedge-forbhypnum moss bog located along the western boundary
of the Arangatuiskii bog massif at a distance of 300–
500 m from the shore of Barguzin Gulf. Samples were
collected from a water-logged area where microbial
fouling occur on plants in the water layer. Points 4 and
5 are small bog areas, the surface of which is the home
of the discharge of deep-seated thermal waters from
the Kulinye Bolota mineral spring. Point 6 – sample
collected directly above the spring that immersed as a
result of a rise in the water table of Lake Baikal. Point
7 – water sample from Chivyrkuiskii Bay of Lake
Baikal.
A hydrochemical analysis of water was carried out,
HYDROCHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF BOG ECOSYSTEMS
299
Fig. 1. Study area.
(1) –(7) sampling points.
following generally accepted techniques [9]. Water
and bottom sediment samples were collected with
Molchanov’s bathometer, and with the stratometer. In
freshly collected samples, we determined pH, СО2 and
О2 concentrations, and biogenic elements. The numbers
and activity of microorganisms were determined under
laboratory conditions: cellulolitics and proteolitics –
by the method of effective dilutions in Pfennig’s liquid
medium with substrates (filter paper and peptone),
and amilolitics and sulfate-reducing bacteria – on
Pfennig’s dense medium with substrate (starch), and
on Widdel’s medium [10]. The composition of gases
was studied with gas-liquid chromatograph М 3700
(detector – catarometer, carrier gas – argon). СО2 was
determined with column Sovpol B (3 m in length,
and 3 mm in diameter), and methane, hydrogen and
oxygen – with column Molseive 5A (3 m in length, and
2 mm in diameter); the chromatography conditions:
30ºС×70ºС×90ºС.
The rate of microbiological processes was
determined by radio isotope methods in different
modifications [11–12]. Upon introducing the radioactive
label into the sample, the samples were incubated
in situ for 12–24 hr. As labels, we used uniformly
labeled solutions: for determining the intensity of
dark fixation of СО2 and autotrophic methanogenesis
– NaH14СO3, for sulfate reduction – Na235SO4, and
for methane oxidation – 14СН4. Upon completion of
GEOGRAPHY AND NATURAL RESOURCES
Vol. 33
incubation, the samples were fixed with 0.2–0.4 mL
of 40% formalin, and 1 mL of 20% zinc acetate was
additionally introduced into samples containing 35S2–.
A subsequent processing was carried out according to
methods reported in [11, 13]. Radioactivity of the fixed
samples was determined with liquid scintillation counter
RackBeta (LKB, Sweden).
DISCUSSION
A small depth of the aeration zone, and a relatively
high water permeability of the peats of the Arangatuiskie
lake-bog formations are favorable for an intimate
moisture exchange between groundwater/bog waters,
the aeration zone and the atmosphere. In the aeration
zone there occurs vadose water produced by the thawing
of ice inclusions in peats. The characteristic properties
of the winter-spring season are, to a significant extent,
determined by the character of snow cover distribution
and disappearance. Seepage of snowmelt waters
through the frozen peat layer causes an abrupt rise of
groundwater/bog waters with the mean rate of 2 cm per
day, reaching a level 0.2–0.4 m above the day surface.
After the disappearance of snow, groundwater/
bog waters are involved in the formation of the water
balance. As a result of depletion of snowmelt waters and
maximum possible evaporation, their level decreases
to a summertime minimum. A rise is concurrent with
No. 4
2012
300
KHAKHINOV et al.
summertime rainfall; however, a marked effect is
produced only when the value of its ten-day amount
exceeds 20 mm. During the period of rainfall, the
groundwater/bog water table rises to the day surface, so
that most of the bogs turn into quagmires. At the onset
of peat freezing and cessation of rainfall in the first
ten-day period of October, the groundwater/bog water
table decreases to a winter-equilibrium minimum. The
hydrogeological conditions are discussed at greater
length in [14].
The rise of the water level in Lake Baikal involved
a disturbance to the regime of subterranean waters and
the pre-existing water balance, and a redistribution of
overland and subterranean runoffs, which affected the
natural landscapes and the state of soil cover. According
to the topographic maps from the year 1954, the Burtui
river emptied into Lake Baikal in the area of Barguzin
Gulf. Later, within the confines of the isthmus of
Svyatoi Nos Peninsula, the river changed the direction
of its course. At present the river flows into Lake
Arangatui where almost impassable quagmires came
into existence.
A deceleration of the runoff causes changes in the
chemical composition of bog waters. The mineral
bed of the bogs consists of carbonate loams, which
affects the hydrochemical regime and gives rise to bog
waters enriched with mineral matter. The reserves of
biogenic substances are created mainly biologically;
the main source for them is provided by mineral rock
experiencing swamping.
Groundwater shows mostly a hydrocarbonate,
calcium, calcium-manganese and sodium makeup, and
less commonly a hydrocarbonate-sulfate makeup, with
a mixed cationic composition; usually, mineralization
does not exceed 0.6 g/dm3. In a summer season,
mineralization of bog waters and groundwater is
increased due to evaporative concentration and capillary
attraction of moisture from deep-seated horizons.
Areas with shallow occurrence of subterranean waters
develop salinization processes, the chemistry of which
is varied: sulfate- and chloride-hydrocarbonate, sulfatesoda, and soda-chloride. The behavior of the processes
of salinization and formation of such a variety of salts
within a relatively small territory demands further
detailed investigation.
Small streams that form within the bog show
elevated concentrations of Ca2+, HCO3-, SO42-, NH4+,
and NO2-, a high mineralization, and significant contents
of organic matter. The highest contents of almost all
microcomponents are observed along the margin
of the bog in the elevated part and in waterlogged
forests. In quagmires and tributaries, relatively large
concentrations of trace elements undergo sorption on
fine dispersed particles of metal oxides and humic
acids; smaller amounts of trace elements are removed
from solution and concentrate in the upper parts of the
bogs on peats [14].
Bog waters are neutral waters. Near a mineral
source, the pH values increase. In a summer season,
surface water temperature in the bogs differs only
slightly from air temperature. The water temperature
in the bog waters at the time of our investigation was
32–34 ºС; in the gryphon of a mineral spring, it reached
62–65 ºС. Compared to the waters of Chivyrkuiskii
Bay, the bog waters are enriched with organic matter,
which is confirmed by high values of COD and humic
acids, as well as by the occurrence of nitrites and by
elevated contents of Fetot. The largest BOD values were
observed in samples collected at point 6, suggesting
a high activity of microbial communities (with the
numbers of aerobic saprophytes reaching 108 cells/mL)
(Table 1).
Gases released from bogs are nitrogen-methane
(points 2 and 4) and methane-nitrogen gases in their
composition. (points 1, 3, and 5). The nitrogen content
reaches 86%; a relatively high content of methane, up
to 76%, was revealed. The content of carbon dioxide in
samples reaches 5%. The absence of СО2 in gas samples
collected at points 4 and 5 is attributed to its fixation by
alkaline waters of the spring, and to its passage into the
forms of carbonic acid (Table 2).
Bogs are the home to intense activity of
microorganisms, which is facilitated by the presence
of favorable hydrochemical parameters of water, and
by rich contents of autochthonous and allochthonous
organic and mineral matter. Microorganisms are
involved in organic matter production and destruction,
the production of biogenic gases, and in the formation
of aero- and anaerobiosis in waters and bottom
sediments of bogs. Among the indicators of activity
of the microbial community is dark assimilation of
СО2 [13] – a process resulting in the production of
organic matter. Assimilation can occur in the light (in
the process of photosynthesis) as well as in darkness
(dark assimilation or dark fixation of СО2). The rate
of dark assimilation is an integral indicator of activity
of the entire microbial community in the ecosystem.
The intensity of dark fixation of carbon dioxide in the
biotopes under study is 0.20–2.88 mg of С/dm3 per
day (Fig. 2, a). The highest activity of the microbial
community is observed in biotopes located in the
vicinity of a thermal spring.
In the case of intense activity of aerobic
microorganisms, the water and bottom sediments
develop reductive conditions. In a peat deposit with
peat not exceeding 0.7 m in thickness, the 0.3-m layer
sustains oxidizing conditions (500–900 mV), with a
decrease in Eh from –140 to –180 mV observed down
the profile. When the values of Eh are low, anaerobic
microorganisms show active behavior. In the terminal
stages, sulfate-reducing and methane-forming bacteria
are involved in organic matter destruction. The rate of
sulfate reduction in the bog biotopes under study varied
from 6.35 to 16.02 mg S/(dm3∙day) (see Fig. 2, b).
Another terminal stage of organic matter destruction is
the methanogenesis. These two processes are thought of
as being competitive with each other. The autotrophic
and acetoclastic methanogenesis was determined (see
GEOGRAPHY AND NATURAL RESOURCES
Vol. 33
No. 4
2012
301
HYDROCHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF BOG ECOSYSTEMS
Table 1. Hydrochemical composition of bog ecosystems on the Svyatoi Nos isthmus of Lake Baikal
Parameters
Т, ºC
рН
BOD, mg/dm3
О2, mg/dm3
СО2free, mg/dm3
Mineralization, mg/dm3*
НСО3-, mg/dm3
СО32-, mg/dm3
SO42-, mg/dm3*
Сl-, mg/dm3
NO3-, mg/dm3
NO2-, mg/dm3
РО43-, mg/dm3
Са2+, mg/dm3
Mg2+, mg/dm3
Na++К+, mg/dm3*
NH4+, mg/dm3
Fetot, mg/dm3
1
22
7.08
0.63
4.3
n/d
190
79.3
n/d
10.75
1.9
0.17
0.079
0.076
11.3
2.6
10.6
n/d
0.63
2
22
6.70
1.71
3.5
n/d
210
134.2
18
12.9
3.0
0.26
0.024
0.107
10.8
3.9
12.5
0.008
0.73
3
19
6.70
0.08
2.0
4.4
225
152.5
30
9.05
3.0
0.50
0.014
n/d
17.8
2.8
15.7
0.460
1.80
Sampling points
4
34
9.36
2.96
0.3
n/d
–
123.0
78
–
30.2
1.20
0.044
0.034
3.8
6.0
–
0.066
1.15
5
32
8.96
3.33
0.4
n/d
–
195.2
60
12.0
35.6
1.22
n/d
0.037
4.1
6.0
18.2
0.130
0.95
6
65
9.50
4.08
5.1
26.4
290
366.0
108
16.0
32.6
0.26
0.003
0.006
48.1
10.7
22.7
0.280
0.28
7
14
7.95
–
–
–
145
86.4
–
9.6
0.8
0.70
–
–
16.1
3.2
9.8
–
0.18
Note. n/d – not detected, “–” – not determined, *samples were collected in the wintertime.
Table 2. Qualitative and quantitative composition of marshgases (%)
Sampling
points
1
2
3
4
5
Н2
CO2
O2
N2
CH4
0
0
0
0.3
0
2
4
5
0
0
2
1
0
2
4
18
55
42
86
44
76
40
53
12
52
Fig. 2, c, d) – methane formation was largely autotrophic
in all the bog biotopes used in the study.
The rate of autotrophic methane production in
bottom sediments and microbial mats varied from
1.9 to 284.3 μL СН4/(dm3∙day). The highest rate of
methane production was revealed in the microbial mat
of point 3. In bottom sediments of points 4 and 5, the
methanogenesis was proceeding at a lowest rate – 2.7
and 1.9 μL СН4/(dm3∙day), respectively. Methane is
produced from acetate in bog ecosystems at a lower rate
– from 0.25 to 2.15 μL СН4/(dm3∙day). The highest rate
of acetoclastic methanogenesis was revealed at point
3. In microbial mats, the activity of the methanogenic
community is higher than that in the bottom sediments
of these same biotopes.
GEOGRAPHY AND NATURAL RESOURCES
Vol. 33
Minus values of Eh in bogs occur in deeper soil
layers where anaerobic processes can have a much
higher intensity. The evidence for this is provided
by the fact that the composition of liberated marshgas shows a high percentage of methane (see Table
2). Methane produced under reductive conditions
undergoes oxidation by a highly specialized group
of bacteria, methanotrophs, in aerobic settings. The
activity of these bacteria in the bog ecosystems under
study varied from 33.9 to 181.6 μL СН4/(dm3∙day). The
highest intensity of methane oxidation was observed in
bottom sediments of a mineral spring.
The values of intensities, and the balance equations
of microbial processes can be employed to calculate
the number of organic carbon used by bacteria in
the production of methane and hydrogen sulfide
[13]. Sulfate reduction consumes 5.5 to 12.7 μg С/
(dm3∙day). The process of autrophic and acetoclastic
methanogenesis consumes 7.6 to 657.0 and 0.04 to 0.48
μg С/(dm3∙day), respectively. The microbial community
uses 7.6 to 657.0 μg С/(dm3∙day) for methane
production, whereas sulfate reduction consumes 6.5
to 12.3 μg С/(dm3∙day). Furthermore, most of methane
is produced by autotrophic methanogenes which
use in the synthesis hydrogen and carbon dioxide –
products of organic matter destruction. Acetate-using
methanogenes consume in the synthesis of methane up
to 0.50 μg С/(dm3∙day). Upon determining the activity
No. 4
2012
302
KHAKHINOV et al.
Fig. 2. The rate of microbiological processes in bottom sediments and microbial mats of bog biotopes.
(а) dark fixation of СО2, (b) sulfate reduction, (c) autotrophic methanogenesis, (d) acetoclastic methanogenesis.
of sulfate reducers, it was shown that they synthesize
up to 17.5 μg Н2S/(dm3∙day). In bog biotopes with
neutral pH values and with fresh water, a dominant
terminal process is represented by methanogenesis,
whereas in alkaline biotopes wit mineralized water the
sulfidogenesis is comparable to methane formation.
Also, the bog ecosystem creates anaerobic conditions
which are favorable for burial of organic matter in
bottom sediments.
The labeled methane-based radioisotope technique
was used to determine the distribution of carbon in
methane. In the process of methane oxidation, from
8 to 22% of carbon is incorporated in the biomass of
cells and in organic exometabolites, with 88 to 92% of
labeled methane passes into СО2. Methane undergoes
the highest oxidation in biotopes at a mineral spring.
A quantitative assessment of the activity of
microorganisms shows that aerobic and anaerobic
bacteria take an active part in the cycle of matter and
energy in the bog ecosystem of the isthmus of Svyatoi
Nos Peninsula. Microorganisms are involved in the
processes of organic matter production and destruction,
formation and intake of gases, and transformation of
biogenic and abiogenic substances which are supplied
in transit from bogs to Lake Baikal.
CONCLUSIONS
As a result of a rise in the water table of Lake Baikal, the
bog formations of the Svyatoi Nos isthmus are evolving
under new conditions, with an increase in water-logged
areas and with an accelerated development of bogs
without a pronounced anthropogenic factor in the overall
natural development. There are taking place concurrent
changes in development directedness of the isthmus’
ecosystem as a whole which are associated primarily
with hydrological, hydrochemical and characteristics
of bogs. The hydrochemical composition of the bog
biotopes has transformed, and there has occurred a
particularly clearly pronounced intensification of the
microbiological processes influencing the formation
processes of chemical composition of waters.
GEOGRAPHY AND NATURAL RESOURCES
Vol. 33
No. 4
2012
HYDROCHEMICAL AND MICROBIOLOGICAL CHARACTERISTICS OF BOG ECOSYSTEMS
ACKNOWLEDGMENTS
This work was done with financial support under
SB RAS integration projects (No. 38 and No. 95),
and within the programs “Basic Research and Higher
Education” (NOTs–017 “Baikal”) and “Development
of the Scientific Potential of Higher School”
(RNP.2.1.1/2165).
8.
9.
REFERENCES
1. Bakhnov, V.K., Biogeochemical Aspects of the Bog-
2.
3.
4.
5.
6.
7.
Forming Process, Novosibirsk: Nauka, 1986 [in
Russian].
Dobrodeev, O.P., Balance and Resources of Free Oxygen
of Biosphere, Vestn. Mosk. un-ta. Ser. geogr., 1977,
no. 2, pp. 58–62 [in Russian].
Zavarzin, G.A., Biogas and Small-Scale Power
Generation, Nature, 1987, no. 1, pp. 67–79 [in
Russian].
Lopatin, V.D., On a New Interpretation of the Definition
of Bog, Ekologiya, 1986, no. 1, pp. 70–72 [in Russian].
Lopatin, V.D., On the Most Important Ecological
Peculiarities of Bogs, Ekologiya, 1977, no. 6, pp. 419–
422 [in Russian].
Baird, A.J., Hydrological Investigations of Soil Water
and Groundwater Processes in Wetlands, in Hydrology
and Hydrochemistry of British Wetland, ed. by J.M.R.
Hughes and A.L. Heathwaite, Chichester: John Wiley &
Sons Ltd., 1995, pp. 111−130.
Lyakhova, I.G., On the Singling Out of Baikal’s
GEOGRAPHY AND NATURAL RESOURCES
Vol. 33
10.
11.
12.
13.
14.
No. 4
303
Southeastern Shore as a Special Peat-Bog Area, in
Problems of the Ecology of the Baikal Region, Irkutsk:
Izd-vo Limnologicheskogo in-ta SO RAN, 1982 [in
Russian].
Lyakhova, I.G. and Kosovich, I.G., The Bogs of the
Baikal Region and Their Environmental Significance,
in Unique Wildlife Objects Within the Lake Baikal
Watershed Basin, Novosibirsk: Nauka, 1990 [in
Russian].
Fomin, G.S., Water. Monitoring of Chemical, Bacterial
and Radiation Safety According to International
Standards: Encyclopedic Handbook, Moscow: Protektor,
2000 [in Russian].
Romanenko, V.I. and Kuznetsov, S.I., The Ecology of
Fresh-Water Microorganisms, Leningrad: Nauka, 1974
[in Russian].
Belyaev, S.S. and Ivanov, M.V., Radioisotope Technique
for Determining the Bacterial Methane Formation Rate,
Mikrobiologiya, 1975, vol. 44, issue 1, pp. 166–168 [in
Russian].
Ivanov, M.V., Use of Isotopes in Studying the Intensity
of the Sulfate Reduction Process in Lake Belovod’,
Mikrobiologiya, 1956, vol. 25, issue 6, pp. 306–309 [in
Russian].
Kuznetsov, S.I., Saralov A.I. and Nazina, T.N.,
Microbiological Processes of Carbon and Nitrogen
Cycle in Lakes, Moscow: Nauka, 1985 [in Russian].
Namsaraev, V.V., Khakhinov, V.V. and Turunkhaev, A.V.,
The Bog Ecosystems on the Isthmus of Svyatoi Nos
Peninsula, Geografiya i prirod. resursy, 2009, no. 4,
pp. 66–71 [in Russian].
2012